Dayton usually has a fairly decent show. They broadcast it on TV in the area and from what I've seen it's pretty good. If you're in town for it (it's usually mid to late July) you should check out the US Air Force Museum too, it's pretty cool. The airshow is at Dayton International Airport, and the Museum is at Wright-Patterson AFB. I've been told there's a good show at Pattrick AFB near Melbourne, Florida too.

Did you get a chance to check out the Celebration of Flight? I didn't think it was all that great. There was some interesting stuff, but I expected more. USAF Museum has my vote for best aviation thing around here.